Publications by authors named "Mark R Fowler"

Olmesartan is a commonly used antihypertensive medication belonging to the class of angiotensin II receptor blockers. Though generally well-tolerated, olmesartan can rarely cause olmesartan-associated enteropathy (OAE) with non-bloody diarrhea, weight loss, abdominal pain, and vomiting. Patients may develop enteropathy months to years after drug initiation.

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The PD-1/PD-L1 pathway plays a critical role in the physiologic inhibition and modulation of the immune response in normal tissue. Many tumors evade immune detection and response by upregulating PD-L1 expression. Humanized monoclonal PD-1 and PD-L1 antibodies have proven as both tolerable and effective treatment in many neoplasms.

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Sarcoidosis is a granulomatous disease of unknown etiology. Although sarcoidosis is a systemic disease, there appears to be a predilection for involvement of certain organs. The pulmonary system is the most commonly affected system among all racial groups.

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Objectives: The aim of this study was to determine the prevalence of bile cast nephropathy (BCN) in autopsied cirrhotic patients and to correlate BCN with clinical and laboratory data to direct attention to this underrecognized renal complication of liver failure.

Methods: We assessed 114 autopsy cases of cirrhosis for the presence of renal intratubular bile casts using Hall stain for bile. Presence of bile casts was correlated with etiology of cirrhosis, clinical and laboratory data, and histologic findings.

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Background: An efficient method for the identification of medicinal plant products is now a priority as the global demand increases. This study aims to develop a DNA-based method for the identification and authentication of plant species that can be implemented in the industry to aid compliance with regulations, based upon the economically important Hypericum perforatum L. (St John's Wort or Guan ye Lian Qiao).

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The nuclear ribosomal internal transcribed spacer (ITS) sequences of eight Hypericum species were used to design H. perforatum-specific PCR primers by identification of short "microcode" sequences characteristic of the target species. These were tested with three vouchered H.

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Modulation of the L-type Ca(2+) channel (LTCC) by sorcin was investigated by measuring the L-type Ca(2+) current (I (Ca,L)) in isolated rabbit ventricular myocytes using ruptured patch, single electrode voltage clamp in the absence of extracellular Na(+). Fifty millimolars EGTA (170 nM Ca(2+)) in the pipette solution buffered bulk cytoplasmic [Ca(2+)], but retained rapid Ca(2+)-dependant inactivation of I (Ca,L,). Recombinant sorcin (3 microM) in the pipette significantly slowed time-dependant inactivation (tau (fast): 8.

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We examined the modulation of the cardiac L-type Ca(2+) channel (LTCC) by the regulatory protein sorcin and tested the hypothesis that modulation occurred by direct interaction. Whole-cell patch-clamp recordings were made on native rabbit ventricular myocytes and HEK 293 cells expressing cardiac alpha(1C) subunits. In ventricular cells, sorcin increased peak current when using either Ca(2+) or Ba(2+) as charge carriers.

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Age and hypertension contribute significantly to cardiac morbidity and mortality, however the importance of each during the progression of hypertrophy is unclear. This investigation examined the effect of age and hypertension on Ca(2+) handling in rat ventricular myocytes by comparing a genetic model of hypertension and cardiac hypertrophy (spontaneously hypertensive rat, SHR) with its normotensive control (Wistar-Kyoto rat, WKY) at 5 and 8 months of age. Experiments were performed on single left ventricular myocytes isolated from SHR or WKY hearts.

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Changes in cellular calcium (Ca(2+)) handling are thought to underlie the altered contraction that occurs during cardiac hypertrophy and failure. Recent work has highlighted the importance of t-tubules in the control of intracellular Ca(2+). The present study was performed to investigate whether changes in the distribution of I (Ca) between the surface and t-tubule membranes might contribute to the altered Ca(2+) handling observed during compensated hypertrophy in the spontaneously hypertensive rat (SHR).

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Hypertension-induced cardiac hypertrophy alters the amplitude and time course of the systolic Ca2+ transient of subepicardial and subendocardial ventricular myocytes. The present study was designed to elucidate the mechanisms underlying these changes. Myocytes were isolated from the left ventricular subepicardium and subendocardium of 20-wk-old spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY; control).

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A global and transient rise of intracellular Ca2+ (Ca2+i) is central to the operation of pump-leak coupling in the frog early distal tubule (EDT). The endoplasmic reticulum (ER) is the site of this Ca2+ release and reuptake; however, it is likely that other intracellular pools, such as mitochondria, also contribute to cellular Ca2+ homeostasis. The present study was performed to seek evidence of mitochondrial Ca2+ transport in the frog EDT.

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Objective: Recent work has suggested that Na(+)/Ca(2+) exchange (NCX) and L-type Ca(2+) current (I(Ca)) are located predominantly in the t-tubules of cardiac ventricular myocytes, which therefore represent a microdomain for the regulation of intracellular Na(+) (Na(i)) and Ca(2+) (Ca(i)). The aim of this study was to investigate the role of the t-tubules in the response of Ca(i) and contraction to interventions that alter the transsarcolemmal Na(+)gradient.

Methods: Enzymatically isolated and detubulated Wistar rat ventricular myocytes were investigated using fluorescence microscopy and optical detection of cell length.

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The early distal tubule (EDT) of the frog nephron, similar to the thick ascending limb in mammals, mediates the transepithelial absorption of NaCl. The continued absorption of NaCl in the face of varying Na(+) load is maintained by coordination of the activity of ion-transporting proteins in the apical and basolateral membranes, so-called pump-leak coupling. Previous studies identified intracellular Ca(2+), originating from an intracellular Ca(2+) store, as playing a key role in pump-leak coupling in the EDT (Cooper GJ, Fowler MR, and Hunter M.

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Sugar beet cells maintained in the stationary phase of the batch culture cycle for 2 or more days have been shown to exhibit many of the characteristics of quiescent (G ) cells. When such cells were subcultured into fresh medium they progressed through a period of DNA synthesis to a highly synchronised first division, 6 days after subculture. The onset of DNA synthesis and cell division were each delayed by 2 days relative to the timing of the events when the cells were subcultured immediately before entry into the stationary phase.

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